Download PatternFinder here (Windows Executable File, 112K)

 INSTRUCTIONS:

1) Open PatternFinder by double-clicking on it.

2) Click on load input picture to select an image file.

 

3) Choose the bitmap file to load and click ok. (For best results, bitmaps should be in black & white format, and be no larger than 100 by 100 pixels.)

4) Once the bitmap file has loaded, click on load the table in to convert the bitmap into the pattern matrix. Each cell in the pattern matrix corresponds to a pixel in the bitmap, with 1 given to areas that are black (corresponding to a pattern) and a 0 to areas that are white. The control picture that appears next to your bitmap is the area is a visual rendering of the pattern matrix.

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5) To change the size of the probing area for the minimum distance matrix, use the probe square slider. As a general guideline, the probe square should be at least the size of the largest dimension of a unit cell. If this dimension is not known, then the probe square should be set at its maximum value.

6) Once the probe square value is set, then click on make min distance matrix to execute the determination of the minimum distance matrix. The minimum matrix is found by scanning each cell in the pattern matrix; if there is no pattern present, nothing happens. If there is a pattern present in that cell, then the cell is set as the center of the probe square, located in the minimum distance matrix. The distance from each cell in the probe square to the center of the probe square(pattern) is then calculated. If this distance is less than the current distance for the cell in the minimum distance matrix, then the cell is updated with a new minimum distance; otherwise, the cell is left unchanged.

 7) When the pattern in the control picture has turned green and the progress bar is at 100%, the determination of the minimum distance matrix is complete. Click on Show to display a grayscale rendering of the minimal distance matrix in the control picture. Use the grayscale control slider to adjust the contrast of the control picture. Click on Save Picture to save a bitmap of the control picture at any time. These files are saved to the folder that the input picture was loaded in.

8) To show the unit cell boundaries, click on Extract Ridges. This will display the local maxima of the minimum distance matrix.

Sample Patterns (To save, right-click and select “Save picture as”)